Granted Patent
Utility
US 6,809,899 · App. 10/751,215
Magnetic heads for perpendicular recording with trapezoidal pole tips
Inventors:
Yingjian Chen, Yugang Wang, Francis H. Liu, Xizeng Shi, Kyusik Sin, Hugh C. Hiner
Patented Case
View Patent ↗
Granted: Oct 26, 2004
Filed: Dec 31, 2003
Inventors
Yingjian Chen
Yugang Wang
Francis H. Liu
Xizeng Shi
Kyusik Sin
Hugh C. Hiner
Assignee (at issue)
WESTERN DIGITAL (FREMONT), LLC
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.